Vacuum type circuit breaker

ABSTRACT

For converting a particular existing oil circuit breaker into a vacuum-type circuit breaker, a conversion assembly is provided which can be easily incorporated into the circuit breaker after the circuit breaker has been stripped of certain key components. The conversion assembly comprises a frame on which vacuum interrupters, their operating mechanism, and an interconnecting linkage are mounted and suitably adjusted in the factory. Conversion is effected by attaching this frame to the top of an existing cell of the circuit breaker in place of the previouslyused cap and thereafter electrically connecting the vacuum interrupters in circuit with existing lead-in conductors.

United States Patent Bohlinger et al; 1 Aug. 7, 1973 i 1 VACUUM TYPE ClRCUlT BREAKER 2,469,203 5 1949 Palme et al. 200 144 B t 4 3 303,309 21967 Fl h t l 200 144 [75] Inventors: Arthur L. Bohlinger, Newtown Iursc em 6 a l B EW si z ir; Mlner Primary Examiner-Robert S. Macon er oo Attorney-J. Wesley Haubner, William Freedman [73] Assignee: GeneralElectric Company, et

Philadelphia, Pa. I

[57] ABSTRACT [22] Fil d Jvlilille 717090742" 7 For converting aparticular existing oil circuit breaker 21 A L N .1 262,582 into avacuum-type circuit breaker, a conversion as- 1 pp 0 sembly is providedwhich can be easily incorporated into the circuit breaker after thecircuit breaker has [52] U.S. CI 200/144 B, 200/150 R been tripped 0fcertain key eomponen[s The conver- [51] Int. Cl. 01h 33/66 ign assemblycomprises a frame on which vacuum in- [58] Field Of Search R, 150 E, terupte s their perating mechanism and an inter- Z 144 150 G connectinglinkage are mounted and suitably adjusted in the factory. Conversion iseffected by attaching this [56] References Cited frame to the top of anexisting cell of the circuit UNITED STATES PATENTS breaker in place ofthe previously-used cap and there- 1 113 ()87 10 1914 Ball 200 150 Eafterelectrically connectingthe Vacuum imerruPmi" 1,720,413 7 1929Greenwood 200/144 B Circuit with misting lead-in Conductorsl,783,27912/1930 Burnham ZOO/144 B 1,801,736 4 1931 Greenwood 200 144 B 5 5 DrumF'gures 1,936,492 ll/l933 Whitehead ZOO/I50 G PATENIEDMJB H915 3,751,617

summra PR/OR 2/ 2/ ART /2 VACUUM TYPE CIRCUIT BREAKER BACKGROUND Thisinvention relates to a vacuum-type circuit breaker and, moreparticularly, to a conversion assembly that can be used for converting aparticular existing oil circuit breaker into a modern vacuum-typecircuit breaker and also to a method of making such a converson.

A type of oil circuit breaker that has been in widespread use since theearly 1900s is General Electric Companys II-type circuit breaker, anexample of which is disclosed in U.S. Pat. No. 1,113,087-Ball, assignedto the assignee of the present invention. There have been manyvariations in this I-I-type circuit breaker, but the basic organizationof the circuit breaker has remained essentially the same. This basicorganization has comprised: (I) an enclosing cell made either of masonryor metal and having a horizontallyextending base near the bottom of thecell, (2) horizontally-spaced insulators supported on the base, (3)oiltype interrupters mounted atop said insulators, (4) generallyvertically-extending contact rods within said cell extending into saidinterrupters, (5) a cross-bar within said cell mechanically connectingsaid contact rods, (6) a frame mounted atop said cell, (7) an operatingmechanism mounted atop said frame, and (8) an operating rod extendingbetween said mechanism and said cross-bar.

Beginning with the successful development in the late 1950s of vacuuminterrupters capable of handling short circuit currents, there has beena progressively increasing shift from oil to vacuum-type circuitbreakers. The vacuum-type circuit breaker has many advantages over theoil-type circuit breaker, some of which as pointed out in US. Pat. Nos.3,025,375-Frank, 3,163,735-Miller, and 3,594,524- Heintz, all assignedto the assignee of the present invention. Among these advantages are thefact that the vacuum interrupter is a sealed device and there are thusno hot arcing products which must be vented or which could impairinsulating properties outside the interrupter, noise and mechanicalshock are much reduced, and maintenance is easier and is required lessfrequently.

Certain owners of the I'l-ty'pe oil circuit breaker may wish to availthemselves of these advantages, but they may not be willing tocompletely discard their I-l-type circuit breaker and replace it with avacuum-type circuit breaker. Such complete replacement is expensive,involves time-consuming major reconstruction, and results in the loss ofmany components which maybe entirely adequate for continued long-termservice, e.g., the cell itself, insulators within the cell,instrumentation, associated buses, and bus compartments.

SUMMARY Accordingly, an object of our invention is to provide aconversion assembly which can be used for easily and quickly convertingan oil circuit breaker of the abovedescribed l-I-type to a modernvacuum-type circuit breaker.

Another object is to provide for such a conversion without necessitatingreplacement of the cell itself, insulators within the cell, andassociated bus equipment.

Still another object is to provide a conversion assembly which can beassembled and adjusted as a unit in the factory, and then, in the field,can easily be incorporated in a stripped-down existing circuit breakerto effect the desired conversion.

Another object is to construct the conversion assembly in such a mannerthat once it is located as a unit in the stripped-down circuit breaker,all that is basically required to complete the conversion is toelectrically connect it to the lead-in conductors of the circuitbreaker.

In carrying out our invention in one form, we first remove from theexisting oil circuit breaker referred to hereinabove under Backgroundthe components numbered (3) through (8). We replace these componentswith a conversion assembly comprising: a replacement frame adapted to bemounted atop the remaining cell, a replacement operating mechanismmounted atop said replacement frame, a post insulator projectingdownwardly from said replacement frame and having its upper end securedto said frame, a vacuum interrupter mounted on the lower end of saidinsulator with its envelope extending generally horizontally in aposition beneath said frame, and an operating linkage interconnectingsaid operating mechanism and said vacuum interrupter. When thereplacement frame is mounted atop the cell, a pair of conductive barsare respectively connected between the tops of the insulators numbered(2) and terminals of the vacuum interrupter, and this substantiallycompletes the conversion operation.

BRIEF DESCRIPTION OF DRAWINGS For a better understanding of theinvention, reference may be had to the following description taken inconjunction with the accompanying drawings, wherein:

FIG. I is a side elevational view, partly in section, of a prior art oilcircuit breaker that it is desired to convert into a vacuum-type circuitbreaker.

FIG. 2 is a front view, reduced in size, of the circuit breaker of FIG.1 with certain portions thereof removed for simplicity.

FIG. 3 is a side elevational view, partly in section, of a circuitbreaker originally like that of FIG. I but after having been convertedinto a vacuum-type circuit breaker,

FIG. 4 is an enlarged view showing in section a portion of the circuitbreaker of FIG. 3 in a closed position;

FIG. 5 is an end view of the vacuum-type circuit breaker of FIG. 4.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENT Referring now to FIG. 1,there is shown an existing oil circuit breaker 10of the l-I-typereferred to hereinabove. This circuit breaker comprises a protectivecell 12 made in the illustrated device primarily of masonry. Morespecifically, the illustrated cells back wall 14, its bottom wall 15 andits side walls 17 are of concrete. Its front wall is a metal or woodendoor 18, shown closed, but suitably mounted for opening movement topermit access to the interior of the cell. The top of the cell is aframe 19 of slate or some similar material suitably attached to sidewall 17.

Typically the cell is divided into three side-by-side compartments 21,one for each phase unit of the circuit breaker, as shown in the frontview of FIG. 2. The vertically-extending concrete sidewalls 17 aredisposed between these compartments 21. The cap or frame 19 covers allthree compartments, and the back wall 14 extends across the threecompartments. Since the circuit breaker structure in each compartment isessentially the same, only that in one of the compartments will bedescribed.

Referring now to FIG. 1, in the lower portion of the cell is ahorizontally-extending base 22 on which two horizontally spaced-apartinsulators 24 and 26 are mounted. in FIG. 1, insulator 24 is depicted asbeing the tubular insulating shell of a lead-in bushing 27 thatcomprises a lead-in conductor 28 extending vertically through tubularshell 24. lnsulator 24 has a metal end cap 25 at its upper end tofacilitate the making of an electrical connection to any part mountedthereon. lnsulator 24 also has a mounting flange 29 around its midportion suitably bolted to the base 22. A horizontallyextending bus bar30 is electrically connected to the lead-in conductor 28 at its lowerend. This bus bar 30 extends through back wall 14 via a suitable lead-inbushing 32.

The other insulator 26 is a post-type insulator suitably secured at itslower end to base 22. Bonded to the upper end of insulator 26 is a metalend cap 33. Electrically connected to end cap 33 is the terminal of abus bar 34 that extends horizontally through the back wall 14 via asuitable insulatinb bushing 36.

Mounted atop each of the insulators 24 and 26 is an oil-type circuitinterrupter 40 of the type shown, for example, in the aforesaid US. Pat.No. l,l13,087-Ball. Each of these interrupters comprises anoil-containing housing 41, a stationary contact 42 within the housingelectrically connected to the metal end cap of the supporting insulatorat the lower end of the interrupter, and a cooperating movable contactsupported on a movable contact rod 43 at its lower end. The two contactrods 43 extend vertically and are mechanically connected together by across bar 45 at their upper ends.

For actuating the cross bar 45 to open and close the I breaker, anoperating mechanism diagrammatically shown at 50, is provided, mountedupon the cap 19. This operating mechanism comprises an output crank 52that is driven in a clockwise direction from its position of FIG. 1 toopen the circuit breaker. Crank 52 is connected to cross-bar 45 throughan insulating operating rod 54 that extends through cap l9.

The'electrical circuit through the breaker extends from lead-inconductor 28, through one of the interrupters 40, through cross bar 45,and through the other interrupter 40 to the other lead-in conductor 34.Interruption of this circuit is effected by causing the operatingmechanism 50 to drive cross-bar 45 in an upward direction into a dottedline open position of FIG. 1. Such interruption vaporizes oil within theinterrupters, which is suitably vented from the interrupters.

Assume now that it is desired to convert this existing oil circuitbreaker of FIG. 1 into a vacuum-type circuit breaker. This isaccomplished, first of all, by stripping the existing circuit breaker byremoving the operating mechanism 50 and the cap, or frame 19, on whichit is mounted, the operating rod 54, cross-bar 45, and interrupters 40.Then our conversion assembly 60 of FIGS. 3-5, soon to be described, ismounted atop the cell 12 in place on the frame 19, following which theconversion assembly is electrically connected to the lead-in conductors28 and 34 through conductive bars 130 and 132. This conversion operationwill be referred to in more detail hereinafter.

Referring now to FIGS. 3-5, the conversion assembly 60 comprises threevacuum-type circuit interrupters 62, one for each phase of the circuitbreaker, and a common operating mechanism, diagrammatically shown at 64,for the three vacuum interrupters. For supporting both the operatingmechanism 64 and the vacuum interrupter 62, a horizontally-extendingrigid frame 65 is provided. Suspended from frame 65 are threedownwardly-projecting post insulators 68 that are horizontally-spacedfrom each other so that each is located within one of the compartments21 approximately midway between its sidewalls 17. Each of theseinsulators is suitably attached at its upper end to frame 65 and at itslower end to its associated vacuum interrupter 62, as will soon appearin more detail.

Each vacuum interrupter 62 is of a conventional design such as shown,for example, in the aforesaid US Pat. No. 3,163,735-Miller. Referring toFIG. 4, each of these interrupters comprises a highly evacuated envelope70 comprising a tubular casing 72 of insulating material and end caps 74and 75 joined thereto by vacuum-tight seals. Within the sealed envelopeare a pair of relatively movable contacts 77 and 78. One of the contacts77 is a stationary contact supported on a stationary conductive contactrod 77a extending in sealed relationship through end plate 75. The othercontact 78 is a movable contact supported on movable contact rod 78aextending through the other end cap 74. Flexible metallic bellows79provides a seal about the movable contact rod 78a which allows it to bemoved axially without impairing the vacuum inside the envelope.

Suitably attached to tthe left-hand end cap 74 is a casting 80 of ahighly conductive material such as copper or a copper alloy. Casting 80has a mounting portion 82 at its upper end that is suitably bolted tothe lower end of insulator 68. Thus casting 80 supports interrupter 62on insulator 68. The casting 80 further comprises adownwardly-projecting lug 83 to which an electrical connection isadapted to be made, as will soon be described. Casting 80 iselectrically connected to movable contact rod 78a by suitable means suchas flexible copper braid 84 which does not interfere with freelongitudinal movement of contact rod 78a..

The two terminals of the vacuum'interrupter 62 may be thought of asbeing constituted by the outer end of movable contact rod 78a and by theouter end of stationary contact rod 770, respectively.

The operating mechanism 64 that is provided for operating the threevacuum interrupters can be of any suitable conventional design and,hence, it is shown in block form only. This operating mechanismcomprises a rotatably-mounted output shaft that is rotatable in aclockwise direction from its position of FIG. 4 to open the interruptersand is returnable in a counterclockwise direction into its position ofFIG. 4 to close the interrupters. Coupled to this output shaft 90 arethree cranks 92, one for each interrupter. These cranks 92, which arerespectively aligned with the three interrupters, have their outer endsconnected to the movable contact rod 78a of the interrupters throughinsulating linkages 95.

Each linkage comprises an operating rod 97 of insulating material, theupper end of which is pivotally connected at 98 to crank 92 and thelower end of which is pivotally connected at 99 to a guide link 100.Guide link 100 is pivotally mounted on a stationary pivot 101 carried bycasting 80.

Between the lower pivot 99 and the movable contact rod78a there is awipe mechanism 105 of conventional form through which opening andclosing force is transmitted to the movable contact rod 78a. A wipemechanism of this kind is described in greater detail and claimed in theaforesaid Miller US Pat. No. 3,163,735. In general, this wipe mechanismcomprises an intermediate link 106 of rod form, the end of which ispivotally connected at 108 to the contact rod 78a and the other end ofwhich is pivotally connected with lost motion to the operating rod 97.The connection to operating rod 97 is through the previously-describedpivot 99. Pivot 99 has a transversely-extending hole therethroughslidably receiving intermediate rod 106 to permit motion of pivot 99along the length of rod 106. Disposed between pivot 99 and the other endof intermediate rod 106 is a compression spring 109 encircling theintermediate rod. This compression spring 109 tends to urge pivot 99against a stop 110 fixed to the intermediate rod 106.

When operating rod 97 is driven downwardly toward the contacts 77 and 78are firmly driven into engagement and held in engagement with apredetermined force despite loss of contact material through wear andarc-erosion and without blocking the contacts of the other interruptersfrom engaging should the contacts of one of the interrupters engageahead of the contacts of the others.

For insuring substantially straight line motion of con tact rod 78aduring the above-described closing operation, another guide link 112 ispivotally connected by pivot 108 at one end to the contact rod and atits opposite end is pivoted on the pin 101'. In addition, a slidebearing (not shown) is provided about contact rod 78a and is suitablyfixed to end cap 74. t

Contact-opening is effected by driving operating rod 97 upwardly fromits solid line position of FIG. 4. During initial movement of operatingrod 97 in this upward openingldirection, no opening force is applied tothe movable'contact rod since the pivot 99 is merelysliding along theintermediate rod 106 without driving the intermediate rod. This lostmotion continues until pivot 99 strikes stop 110. When this occurs, anabrupt opening force is applied to movable contact rod 78a, and itseparates contact 78 at high speed from contact 77 to produceinterruption of the circuit.

For supplying force for an opening operation, an opening spring 115 isprovided. This spring 115, which constitutes a part of operatingmechanism 64, is a compression spring bearing atone end on a stationarymember 116 and at its opposite end on a stop 118 fixed to a rod 119connected to crank 92. When output shaft 90 is driven in acounterclockwise direction into its position of FIG. 3, it acts tocompress opening spring 115.

At the end of the closing operation, shaft 90 is latched in its closedposition by a suitable latch (not shown). When such latch is released atthe start of an opening operation, opening spring 115 expands to drivecrank 92 clockwise and operating rod 97 in an upward opening direction.

The rigid frame 65 may be thought of as constituting a skeleton for theassembly on which all of the interrupters 62, the post insulators 68,the operating mechanism 64, and the insulating linkages 95 are mounted.While the assembly 60 is still in the factory, these components 62, 68,64, 95 can be supported on the frame and suitably located and adjustedwith respect to each other. The result is a self-sustaining assemblybuilt around frame 65 as a skeleton, which assembly can be shipped as aunit to a field site and there incorporated into a stripped-down circuitbreaker without requiring any additional adjustments of its majoroperating components 62, 68, 64 and 95. Should any minor adjustments beneeded at the field site, these can be readily effected in view of theself-sustaining character of the assembly and the easy access that canbe had to its components. It will be noted that thiseasy access isavailable even when the conversion assembly 60 is mounted on cell 12since all the key parts inside the cell can be easily reached when celldoor 18 is opened.

Returning to the conversion operation, it was pointed out hereinabovethat the first step in making the conversion at the field site is toremove from the oil circuit breaker of FIGS. 1 and 2 the operatingmechanism 50, the frame 19 on which it is mounted, operating rod 54, thecross bar 45, and the interrupters 40. Then, the above-describedconversion assembly 60 of FIG. 3 is placed atop cell 12, with its frame65 being in substantially the same location as the original frame 19.The new frame 65 is then bolted to the walls of the cell, thus fixingthe frame to the cell and locating one of the vacuum interrupters ineach compartment of the cell midway between the sidewalls of thecompartment. The

next step is to electrically connect the lead-in conductors 28 and 34 ofeach phase to the respective terminals 78a and of the vacuum interrupterin the associated phase. Referring to FIG. 3, this is accomplished ineach phase of the breaker by connecting between end cap 25 of insulator24 and the lug 83 on casting an electroconductive bar and by connectingbetween the exposed outer end of stationary contact rod 77a and end cap33 of insulator 26 another electroconductive bar 132. Suitable clampingbolts are relied upon for interconnecting parts 130 and 83, and asuitable clamp 137 is relied upon for interconnecting parts 132 and 77a.Bar 130 includes an angle conductor 133 at its lower end shaped tofacilitate making the connection to conductive end cap 25 of insulator24; and bar 132 includes a similar angle conductor 134 shaped tofacilitate making the connection with the conductive end cap ofinsulator 26. This basically completes the conversion operation, thougha few finishing touches may be needed, such as attaching a shield to theright hand end of each vacuum interrupter and also electricallyconnecting the control wiring for the operating mechanism.

It will be seen from the above that once the original oil circuitbreaker has been stripped, all that is required, basically, to effectthe conversion is to mount the conversion assembly 60 atop the cell 12and to electrically connect it to the lead-in conductors 28 and 34through the bars 130 and 132. All the mechanically interconnected partsof assembly 60 have already been located and adjusted with respect toeach other at the factory, thus eliminating the need for assembling andadjusting these parts in the field and thus greatly simplifying theconversion operation.

It will also be apparent that the above-described conversion can beeffected without disturbing the basic structure of cell 12, orinsulators 24 and 26, or the buses 30 and 34, or any switches orinstrumentation (not shown) combined with the bus, thus reducing thecost of converting from oil to vacuum interruption.

While we have shown and described particular embodiments of ourinvention, it will be obvious to those skilled in the art that variouschanges and modifications may be made without departing from ourinvention in its broader aspects; and we, therefore, intend herein tocover all such changes and modifications as fall within the true spiritand scope of our invention.

What we claim as new and desire to secure by Letters Patent of theUnited States is:

1. A conversion assembly for use in converting into a vacuum-typecircuit breaker an existing oil circuit breaker that comprises: l a cellhaving a horizontallyextending base in the lower region of the cell, (2)horizontally-spaced insulators supported on said base, (3) oil-typeinterrupters mounted atop said insulators, (4) generallyvertically-extending contact rods within said cell extending into saidinterrupters, (5) a cross-bar within said cell mechanically connectingsaid contact rods, (6) a framemounted atop said cell, (7) an operatingmechanism mounted atop said frame, and (8) an operating linkageextending between said mechanism and said cross bar, after said existingcircuit breaker has been stripped by removal of said interrupters,contact rods, cross bar, frame, operating mechanism, and linkage; saidconversion assembly comprising:

a. a replacement frameadapted to be mounted atop said cell,

b. a replacement operating mechanism mounted atop said replacementframe,

c. a vacuum interrupter comprising: an evacutated envelope havingspaced-apart opposite ends, separable contacts within said envelope, amovable contact rod extending through one end of said envelope andsupporting one of said contacts, and spaced terminals at opposite endsof said envelope electrically connected to said contacts,

d. a post insulator projecting downwardly from said replacement frameand having its upper end secured to said replacement frame,

e. means mounting said vacuum interrupter on the lower end of said firstinsulator in such a manner that said envelope extends generallyhorizontally in v a position beneath said frame,

f. a replacement operating linkage at least partially of insulatingmaterial extending between and interconnecting said replacementoperating mechanism and the movable contact rod of said vacuuminterrupter,

g. and a pair of conductive bars for connection, re-

spectively, between the tops of said base-supported insulators and theterminals of said vacuum interrupter.

2. A polyphase conversion assembly as defined in claim 1 in which onephase of the assembly comprises (c), (d), (e), (f) and (g) of claim 1,and another phase of the assembly comprises additional parts constructedas defined in (c), (d), (e), (f) and (g) of claim 1, said replacementframe and said replacement operating mechanism being common to bothphases, the vacuum interrupters of said phases being horizontally spacedfrom each other.

3. An electric circuit breaker comprising:

a. a cell having a horizontally extending base in its lower portion,

b. a pair of horizontally-spaced insulators supported on said base,

0. a frame mounted atop said cell,

d. an operating mechanism mounted atop said frame,

e. a vacuum interrupter comprising: an evacuated envelope havingspaced-apart opposite ends, separable contacts within said envelope, amovable contact rod extending through one end of said envelope andsupporting one of said contacts, and spaced terminals at opposite endsof said envelope electrically connected to said contacts,

f. a post insulator projecting downwardly from said frame and having itsupper end secured to said frame,

g. means mounting said vacuum interrupter on the lower end of said postinsulator in such a manner that said envelope extends generallyhorizontally in a position beneath said frame,

h. an operating linkage at least partially of insulating materialextending between and interconnecting said operating mechanism and thecontact rod of said vacuum interrupter,

i. and a pair of conductive bars respectively connected between the topsof said base-supported insulators and the terminals of. said vacuuminterrupter.

4. A polyphase circuit breaker as defined in claim 3 in which one phaseof the circuit breaker comprises (e), (f), (g), (h), and (i) of claim 3,and another phase of the circuit breaker comprises additional partsconstructed as defined in (e), (f), (g), (h), and (i) of claim 3, saidframe and said operating mechanism being common to both phases, thevacuum interrupters of said phases being horizontally spaced from eachother.

5. A method of converting into a vacuum-type circuit breaker an existingoil circuit breaker that comprises: l) a cell having ahorizontally-extending base in the lower region of the cell, 2)horizontally-spaced insulators supported on said base, (3) oil-typeinterrupters mounted atop said insulators, (4) generallyverticallyextending contact rods within said cell extending into saidinterrupters, (5) a cross bar within said cell mechanically connectingsaid contact rods, (6) a frame mounted atop said cell, (7) an operatingmechanism mounted atop said frame, and (8) an operating linkageextending between said mechanism and said cross-bar; said conversionmethod comprising the following steps:

a. stripping said circuit breaker by removing therefrom saidinterrupters, contact rods, cross-bar, frame, operating mechanism andlinkage,

b. providing a conversion assembly comprising a replacement frame, areplacement operating mechanism mounted atop said frame, a vacuuminterrupter comprising an evacuated envelope containing separablecontacts and having terminals at its opposite ends respectivelyconnected to said contacts, a first insulator projecting downwardly fromsaid replacement frame and having its upper end c. mounting saidreplacement frame atop said cell with said vacuum interrupter withinsaid cell,

(1. providing a pair of conductive bars,

e. and electrically connecting said bars between the tops of saidbase-supported insulators and the terminals of said vacuum interrupter.

. (5/621) i J x I I (115.1117 Mil/x1321) ()ir (1Q il-i iiifi'fiUf-JPatent: No- 1.617 I -])ntcd August 7, 1973 n Arthur L. Bohlinge'r &Richard H. Miller It is cortifiod that error appbars in thenbovca-idontificd patent and that said Letters Patent are herebycorrected 3:; shown below:

Column 1 line 36, change "as" to are Column 3-, line G3,;chn'ge "'on":to of Column 5, line 66, after "counterclockwise" insert --closing--Column 5, Line 67, change "3" to=-.14

Signedain'd sealed this 'l th day of'March 1974.

(SEAL) Attest:

EDWARD M.FLETCHER, J R. v C. MARSHALL 'DANN 'Attesting Officer v Commissioner of Patents CEik'ii z. i-ij/.'i.iil O 2. CO Ell-39811.04!

Patent: No. 3. 751.617 Dated August 7, 1973 Invcnmflg) Axjtl ur L.Bohlinger &' Richard H. Miller .t is certified that error appears in theabovcwidentified patent and that; said Letters Patent arc: herebycorrected as; shown below:

Column 1, line 36, change "as" to are Column 3, line 63, cnnge '"on" toof Column 5, line 66, after "counterclockwise" insert --closing-- Column5, line 67, change "3" to -,4

Signed and sealed this' 19th day of March 1974.

(SEAL) Attest:

EDWARD M.FLETCHER,JR. C. MARSHALL DANN Attesting Officer Commis sionerof Patents

1. A conversion assembly for use in converting into a vacuumtype circuitbreaker an existing oil circuit breaker that comprises: (1) a cellhaving a horizontally-extending base in the lower region of the cell,(2) horizontally-spaced insulators supported on said base, (3) oil-typeinterrupters mounted atop said insulators, (4) generallyvertically-extending contact rods within said cell extending into saidinterrupters, (5) a crossbar within said cell mechanically connectingsaid contact rods, (6) a frame mounted atop said cell, (7) an operatingmechanism mounted atop said frame, and (8) an operating linkageextending between said mechanism and said cross bar, after said existingcircuit breaker has been stripped by removal of said interrupters,contact rods, cross bar, frame, operating mechanism, and linkage; saidconversion assembly comprising: a. a replacement frame adapted tO bemounted atop said cell, b. a replacement operating mechanism mountedatop said replacement frame, c. a vacuum interrupter comprising: anevacutated envelope having spaced-apart opposite ends, separablecontacts within said envelope, a movable contact rod extending throughone end of said envelope and supporting one of said contacts, and spacedterminals at opposite ends of said envelope electrically connected tosaid contacts, d. a post insulator projecting downwardly from saidreplacement frame and having its upper end secured to said replacementframe, e. means mounting said vacuum interrupter on the lower end ofsaid first insulator in such a manner that said envelope extendsgenerally horizontally in a position beneath said frame, f. areplacement operating linkage at least partially of insulating materialextending between and interconnecting said replacement operatingmechanism and the movable contact rod of said vacuum interrupter, g. anda pair of conductive bars for connection, respectively, between the topsof said base-supported insulators and the terminals of said vacuuminterrupter.
 2. A polyphase conversion assembly as defined in claim 1 inwhich one phase of the assembly comprises (c), (d), (e), (f) and (g) ofclaim 1, and another phase of the assembly comprises additional partsconstructed as defined in (c), (d), (e), (f) and (g) of claim 1, saidreplacement frame and said replacement operating mechanism being commonto both phases, the vacuum interrupters of said phases beinghorizontally spaced from each other.
 3. An electric circuit breakercomprising: a. a cell having a horizontally extending base in its lowerportion, b. a pair of horizontally-spaced insulators supported on saidbase, c. a frame mounted atop said cell, d. an operating mechanismmounted atop said frame, e. a vacuum interrupter comprising: anevacuated envelope having spaced-apart opposite ends, separable contactswithin said envelope, a movable contact rod extending through one end ofsaid envelope and supporting one of said contacts, and spaced terminalsat opposite ends of said envelope electrically connected to saidcontacts, f. a post insulator projecting downwardly from said frame andhaving its upper end secured to said frame, g. means mounting saidvacuum interrupter on the lower end of said post insulator in such amanner that said envelope extends generally horizontally in a positionbeneath said frame, h. an operating linkage at least partially ofinsulating material extending between and interconnecting said operatingmechanism and the contact rod of said vacuum interrupter, i. and a pairof conductive bars respectively connected between the tops of saidbase-supported insulators and the terminals of said vacuum interrupter.4. A polyphase circuit breaker as defined in claim 3 in which one phaseof the circuit breaker comprises (e), (f), (g), (h), and (i) of claim 3,and another phase of the circuit breaker comprises additional partsconstructed as defined in (e), (f), (g), (h), and (i) of claim 3, saidframe and said operating mechanism being common to both phases, thevacuum interrupters of said phases being horizontally spaced from eachother.
 5. A method of converting into a vacuum-type circuit breaker anexisting oil circuit breaker that comprises: (1) a cell having ahorizontally-extending base in the lower region of the cell, (2)horizontally-spaced insulators supported on said base, (3) oil-typeinterrupters mounted atop said insulators, (4) generallyvertically-extending contact rods within said cell extending into saidinterrupters, (5) a cross bar within said cell mechanically connectingsaid contact rods, (6) a frame mounted atop said cell, (7) an operatingmechanism mounted atop said frame, and (8) an operating linkageextending between said mechanism and said cross-bar; said conversionmethod comprising the following steps: a. stripping said circuit breakerby removing therefrom said interrupters, contact rods, cross-bar, frame,operating mechanism and linkage, b. providing a conversion assemblycomprising a replacement frame, a replacement operating mechanismmounted atop said frame, a vacuum interrupter comprising an evacuatedenvelope containing separable contacts and having terminals at itsopposite ends respectively connected to said contacts, a first insulatorprojecting downwardly from said replacement frame and having its upperend secured to said replacement frame, means mounting said vacuuminterrupter on the lower end of said first insulator in such a mannerthat said envelope extends generally horizontally in a position beneathsaid frame, and linkage means interconnecting said operating mechanismand one of the contacts of said vacuum interrupter, c. mounting saidreplacement frame atop said cell with said vacuum interrupter withinsaid cell, d. providing a pair of conductive bars, e. and electricallyconnecting said bars between the tops of said base-supported insulatorsand the terminals of said vacuum interrupter.